The PowerBook 100 was a portable subnotebook personal computer manufactured by Apple Computer and introduced on October 21, 1991 at the COMDEX computer expo in Las Vegas, Nevada. Priced at US$2,300, the PowerBook 100 was the low-end model of the first three simultaneously released PowerBooks. Its CPU and overall speed closely resembled those of its predecessor, the Macintosh Portable. It had a Motorola 68000 16-megahertz (MHz) processor, 2 to 8 megabytes (MB) of memory, a -inch () monochrome backlit liquid crystal display (LCD) with 640 × 400 pixel resolution, and the System 7.0.1 operating system. It did not have a built-in floppy disk drive and was noted for its unique compact design that placed a trackball pointing device in front of the keyboard for ease of use.